Oil price has more than halved in the last year, so as OPEC cartel leader, one would expect Saudi Arabia to cut output (and hence force the price up).

But instead they have chosen to maintain supply, despite the financial pain this is causing domestically.

Strategy is to prioritise its own long-term market share, and perhaps to inflict pain on fellow OPEC members Iran and Russia (who Saudi Arabia believes have destructive geopolitical ambitions in the Middle East).